Bottom bracket cup



FIG. 1 is a top view of a bottom bracket cup;

FIG. 2 is a front side view of the design, wherein the rear, right and left side views are identical;

FIG. 3 is a bottom view of the design;

FIG. 4 is a perspective view of the design; and,

FIG. 5 is a bottom perspective view of the design.

The broken lines depict portions of the design that are not claimed. 

The ornamental design for a bottom bracket cup, as shown and described. 